Smooth Push Interference Free Snow Shovel

ABSTRACT

A hand operated snow shovel that will smoothly transition over expansion joints and uneven heights between adjacent surfaces due to the unique design of the leading edge of the blade. The leading edge of the invention is set at an angle to the centerline of the blade to create an offset which effectively makes the leading edge wider than an expansion joint opening and prevents the leading edge from dropping into the expansion joint. In addition, the leading corner of the blade is curved upwards higher than the acceptable height differences in uneven adjacent surfaces. The upwards curve creates a lifting surface for the blade which will cause the leading edge to raise as it is pushed forward allowing the leading edge to smoothly transition from a lower surface to a higher surface as the blade is pushed forward.

CROSS REFERENCE TO RELATED APPLICATIONS

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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OF DEVELOPMENT

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REFERENCE TO SEQUENCE LISTING, A TABLE OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX

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BACKGROUND OF THE INVENTION Field of Invention

This invention relates to a snow shovel blade with a modified leading edge that will permit it to glide smoothly over expansion joints or uneven surfaces when pushing or removing snow.

Problem Solved

Many surfaces consist of a series of concrete slabs in residential, commercial, and public settings such as sidewalks and driveways. These surfaces generally have expansion joints between the slabs as a design feature to reduce internal stresses that could damage the slabs by creating cracks or buckling as temperature changes. From a design standpoint, expansion joints are perpendicular to the edge of the surface which they intersect and typically range from 0.375 inch to 0.500 inch wide. When the ground shifts, individual slabs may move causing the expansion joint to get wider and/or change height creating an uneven surface which creates problems when removing snow.

Current snow shovels include various hand operated implements consisting at a minimum of a blade and handle that are designed to move snow on a surface by pushing and/or lifting the snow.

Snow shovels can have multiple design characteristics for the handle and blade. The blade can be designed for pushing snow, lifting snow or a combination of both. Current snow shovel blades either have a straight leading edge that is perpendicular to the centerline of the blade or a profiled leading edge, such as a diamond or scallops, that are symmetrical to the centerline of the blade.

It is common practice to push a hand operated snow shovel forward parallel to the edge of the surface being cleared which will make the leading edge of the blade parallel to the expansion joint in most cases.

While it is beneficial to have expansion joints between adjacent slabs to prevent damage, these expansion joints can create problems by interfering with the smooth and continuous use of a standard snow shovel during the snow removal process by creating interruptions. These interruptions generally result from:

1. The leading edge of the snow shovel blade will slide along the top surface of the slab being cleared until it drops into the expansion joint opening as it is pushed from one slab to another. When the leading edge of a snow shovel blade drops into an expansion joint an interference is created which will interrupt the snow removal process leading to problems requiring extra effort and time.

2. The leading edge of the snow shovel blade will slide along the top surface of a slab being cleared and will strike the edge of the next slab if it is higher. When the leading edge strikes the edge of a higher slab an interference is created which will interrupt the snow removal process leading to problems requiring extra effort and time.

These problems are commonplace with current snow shovel designs and are resolved by this invention.

BRIEF SUMMARY OF THE INVENTION

This invention can be used to smoothly clear snow from a surface consisting of individual slabs separated by expansion joints with or without uneven surfaces between adjacent slabs.

This is accomplished by a snow shovel where the leading edge of the blade is at an angle to the centerline of the blade and by having the leading corner of the leading edge curve up to create a lifting surface which will strike the edge of a higher slab first causing the blade to lift as it is pushed forward. This is different than common snow shovels in use today where the leading edge is either perpendicular or symmetrical to the centerline of the blade which can create an interference problem as the leading edge attempts to move over an expansion joint.

For this invention, a straight leading edge which is at an angle to the centerline of the blade will create an offset which can be greater in width than the expansion joint opening. Being that the leading edge is effectively wider than the expansion joint opening, the leading edge will not drop down into the expansion joint and will smoothly transition over an expansion joint opening as it will be always supported by the either the trailing slab surface and/or the forward slab surface as it is pushed from one slab to the next.

Given that the leading edge of the snow shovel blade in this invention is at an angle to the blade centerline, one of the snow shovel blade's corners will be positioned ahead of the other as the shovel is pushed forward. The blade corner positioned ahead of the other, the leading corner, will approach the expansion joint first. In this invention the leading corner will have an angled upwards curve creating a rounded lifting surface. When the surface is uneven and the forward slab is higher, the lifting surface of the leading corner will strike the edge of the higher slab first. The force pushing the snow shovel forward will cause the blade to gently rise along the rounded lifting surface allowing the snow shovel leading edge to smoothly transition from a lower slab surface to a higher slab surface much like the rounded front of a snow ski causes the entire ski to move over bumps in the snow. Because the leading edge of the blade for traditional snow shovels are flat, they will strike against a higher surface between slabs causing an interference which stops the snow shovel from going forward. This interference will cause delays and require extra effort which are problems.

This invention will enable a snow shovel to smoothly transition over both expansion joint openings and uneven surfaces and will thus eliminate interruptions which cause delays and require extra effort which are problems with snow shovels in use today.

BRIEF DESCRIPTION OF DRAWINGS

These drawings will become more apparent from the detailed description to follow. Alternate designs than those shown (i.e., handle designs) may be appropriate and these are for illustration only and are not intended to be in any way limiting.

FIG. 1 is a standard snow shovel with a straight blade where the leading edge is perpendicular to the centerline of the blade.

FIG. 2 is a standard snow shovel with a diamond blade where the leading edge is symmetrical to the centerline of the blade.

FIG. 3 is a standard snow shovel with a “U” style handle and a straight blade designed for pushing snow where the leading edge is perpendicular to the centerline of the blade.

FIG. 4 is a standard snow shovel with an angularly adjustable straight blade in relation to the handle where the leading edge is perpendicular to the centerline of the blade.

FIG. 5 is a plan view of a surface (sidewalk) consisting of adjoining slabs separated by expansion joints that are perpendicular to the surface edge they intersect.

FIG. 6 is a plan view of a surface (driveway) consisting of adjoining slabs separated by expansion joints that are perpendicular to the surface edge they intersect.

FIG. 7 is a side view of two adjacent slabs with a snow shovel leading edge in contact with the surface to be shoveled.

FIG. 8 is a plan view of a surface with a standard snow shovel in position to remove snow. Key takeaways are that the shovel will be pushed parallel to the surface edge of the slab and the leading edge of the blade is parallel to the expansion joint.

FIG. 9 is a plan view showing the problem of a standard shovel being stuck in an expansion joint between adjacent slabs since the leading edge was able to DROP into the expansion joint opening.

FIG. 10 is a plan view showing the problem of a standard shovel being stuck on the higher edge of an adjacent slab as it was attempted to be slid from a lower slab to a higher slab.

FIG. 11 is a plan view of the invention showing the unique design characteristics consisting of

-   -   a leading edge at a fixed angle β relative to the blade         centerline.     -   a leading corner with an angled surface α that creates a lifting         surface that will enable the blade to ride over a higher slab         surface edge lifting the blade as it is pushed forward.

FIG. 11A is the front VIEW A-A of the invention blade showing the leading edge and upwards curved leading corner.

FIG. 11B is a side VIEW B-B of the invention showing the upwards rise of the blade's leading corner.

FIG. 12 shows the trigonometric relationship for the arctangent function.

FIG. 13 is the plan view of the invention showing the leading edge straddling an expansion joint as it is pushed over an expansion joint without interruption. A key takeaway is that the forward portion of the leading edge is supported on the forward slab surface and the trailing portion of the leading edge is supported on the trailing slab surface thus preventing it from dropping into the expansion joint.

FIG. 14 is a side view of the invention showing the positioning of the forward corner curved lifting surface to smoothly move from a lower surface to a higher surface without interruption.

DETAILED DESCRIPTION OF THE INVENTION

Hand operated snow shovels (heretofore: ‘snow shovel’) in use today have many different attributes. The materials used, dimensional sizes of the components (length/width/diameter) and methods of attachment can vary. All of which in their various configurations and combinations can be included into this invention.

Most snow shovels 1A, 1B have a single handle 2 and some snow shovels 1C may have a “U” shaped handle 2 both of which can be used in this invention. In these cases, the handle is attached to a stationary blade 3 which can vary in design depending upon whether its intended purpose is to lift snow and/or push snow, FIG. 1, FIG. 2, FIG. 3. The leading edge of the blade is the most forward portion of the blade that contacts the surface being cleared and separates the snow from the surface. In some designs the leading edge 4 is the front portion of the blade 3 which carries or pushes the snow. In other designs the leading edge 4 is a secondary element, generally made of a hardened wear resistant material, that is attached to the front of the blade 3.

There are some snow shovel concepts 1D where the blade 3 can be adjusted angularly θ relative to the handle 2, FIG. 4. The angle is claimed to be beneficial since it provides the ability to direct snow to the right or left as the shovel is pushed forward. However, these are problematic since they are more complex than a fixed blade snow shovel 1A, 1B, 1C due to the number of added components required to adjust the angle of the blade θ. These snow shovels 1D can be more expensive to manufacture and the added components increase the weight of the shovel which is an extreme disadvantage and are more strongly associated with power snow removal systems such as carts, cars, tractors, and motorized plows.

While snow shovels in use today can have many differences, there are common features as identified below for both fixed angle 1A, 1B, 1C and adjustable angle snow shovels 1D.

-   -   The leading edge 4 of the blade 3 is either perpendicular         to the centerline 5 of the blade 3, 1A, 1C, 1D or the leading         edge 4 is symmetrical         to the centerline 5 of the blade 3, 1B.     -   The top surface of the leading edge 4 is flat         , VIEWs W-W, X-X, Y-Y, Z-Z.

The above common features lead to problems during the snow removal process requiring extra effort and increased time to remove snow from surface 6 that consist of slabs 7 separated by expansion joints 8 perpendicular ⊥ to the surface edge 9 that they intersect FIG. 5, FIG. 6.

To remove snow from a surface 6, the leading edge 4 of the blade 3 is placed in contact with the top of the slab 7 resting on the ground 10 and pushed forward from one slab 7 to the next over the expansion joint 8 opening 8A by a force applied to the handle 2 that controls the direction of PUSH, FIG. 7.

Generally, the shovel is pushed forward parallel//to a surface edge 9 of the slab 7 resulting in the leading edge 4 of the blade 3 being parallel//to the expansion joint 8 between slabs 7, FIG. 8.

As the blade 3 is pushed from one slab 7 to the next the leading edge 4 will attempt to travel across the expansion joint 8 between slabs 7 which can create two different problem conditions that require extra effort and added time using snow shovels in use today.

Problem #1 is that the leading edge 4 will DROP into the expansion joint 8 striking the front edge of the adjacent slab 7 creating an interference which interrupts the snow removal process. This requires extra effort and adds time to complete the snow removal process, which is a problem, FIG. 9.

Problem #2 occurs when the ground 10 beneath a slab 7 shifts causing a slab to raise or drop in height compared to the adjacent slab creating an uneven condition 11. When the blade 3 is attempted to be pushed from a lower slab 7C to a higher slab 7D, the leading edge 4 will strike the edge of the higher slab 7D. This will cause an interference which interrupts the snow removal process. This requires extra effort and adds time to complete the snow removal process, which is a problem, FIG. 10.

The invention disclosed here 1E resolves problems #1 and #2 in a low-cost simple manner FIG. 11, FIG. 11A, FIG. 11B.

To resolve problem #1, the leading edge 4A of the snow shovel blade 3 is a straight surface set at an angle β to the centerline 5 of the blade 3. The angle β is calculated such that it creates a design offset OF greater than the width 8A of the expansion joint 8, FIG. 11.

The minimum fixed angle β of the invention 1E is calculated based on the width 3W of the blade 3 and a target offset OF using the standard trigonometric ARCTAN equation below, FIG. 12. A safety factor (SF) can be used in the calculation to make sure that the offset OF is greater than the expansion joint width 8A, FIG. 9, FIG. 11.

Angle (β)=tan⁻¹(OF/3W)

The example below assumes a blade 3 width 3W of 24.0 inch, a safety factor, SF of 2 and an expansion joint design width 8A of 0.500 inch which is typical for many driveways and sidewalks.

EXAMPLE

$\left. {{3W} = {\begin{matrix} 24 & \left( {{typically}W{will}{range}{from}18} \right. \end{matrix}{inch}{to}36{inch}}} \right)$ $\left. {{8A} = {{\begin{matrix} 0.5 & ( \end{matrix}{maximum}{design}{value}} = {0.5{inch}}}} \right)$ $\left. {{SF} = {\begin{matrix} 2 & \left( {{to}{account}{for}{possible}{wider}} \right. \end{matrix}{joint}{situations}}} \right)$ $\begin{matrix} {{OF} = {\left( {8A} \right) \times ({SF})}} \\ {= {(0.5) \times (2)}} \\ {= 1.} \end{matrix}$ $\begin{matrix} {{{Angle}(\beta)} = {\tan^{- 1}\left( {{{OF}/3}W} \right)}} \\ {= {\tan^{- 1}\left( {1./24} \right)}} \\ {= {2.4{degrees}}} \end{matrix}$

When the invention 1E is used to clear snow off a surface 6 with expansion joints 8, the leading corner 12 will cross the expansion joint 8 first as the leading edge 4A is supported by the trailing slab 7A. As the leading edge 4A crosses over the expansion joint 8 support for the leading edge 4A will transition from the trailing slab 7A to the forward slab 7B allowing the entire leading edge 4A to travel smoothly over the expansion joint opening 8 without dropping down thus eliminating problem #1, FIG. 13.

To resolve problem #2, the leading corner 12 is curved upwards a radius 12R, FIG. 11A to create a curved lifting surface 12A at an angle α to the blade centerline 5, FIG. 11. The leading corner 12 radius 12R is selected to create a rise 12S, FIG. 11B greater in height than the maximum acceptable height difference 11 between adjacent slabs 7C, 7D.

When the leading corner 12 has a curved lifting surface 12A this surface will contact the edge of the higher slab 7D first. Instead of coming to an abrupt stop, the force pushing the shovel 1E forward will gently cause the blade 3 to raise as lifting surface 12A slides over the edge of the higher slab 7D much like the curved front end of a snow ski will raise up over obstacles in its path. The lifting of the blade 3 by the contact between the curved lifting surface 12A and the edge of the higher slab 7D will cause the leading edge 4A to raise and smoothly travel over the edge of the higher slab 7D thus eliminating problem #2, FIG. 14. 

What is claimed is that:
 1. A shovel comprising: a blade with a straight leading edge not perpendicular to the centerline of the blade.
 2. A shovel of claim 1, wherein the angle of the leading edge, in relation to the centerline of the blade, is set to create an offset that is wider than the width of an expansion joint opening between adjacent slabs in a surface.
 3. A shovel of claim 1, that will smoothly transition over expansion joint openings without dropping into an expansion joint opening since the leading edge will be wider than the expansion joint opening given the angle of the leading edge relative to the centerline of the blade.
 4. A shovel of claim 1, comprising of a leading edge that is not flat and has a leading corner with an upwards curved surface.
 5. A shovel of claim 4, comprising of an upwards curved surface of the leading corner that is set at a non-perpendicular angle to the blade centerline.
 6. A snow shovel of claim 4, where the upwards curve of the leading corner raises up higher than the acceptable height difference in adjacent slabs.
 7. A shovel of claim 4, that will smoothly transition over a higher edge as the shovel is pushed from a lower slab to a higher slab as the force pushing the snow shovel forward will cause the blade to raise as the curved lifting surface rides over a higher slab edge. 